29 July 2012

The Conversion of a Climate-Change Skeptic

“The decadal land-surface average temperature using a 10-year
moving average of surface temperatures over land. Anomalies are relative
to the Jan 1950 – December 1979 mean. The grey band indicates 95%
statistical and spatial uncertainty interval.” A Koch-funded
reanalysis of 1.6 billion temperature reports finds that “essentially
all of this increase is due to the human emission of greenhouse gases.”

The Berkeley Earth Surface Temperature Study (BEST) is poised to
release its findings next week on the cause of recent global warming.

CALL me a converted skeptic. Three years
ago I identified problems in previous climate studies that, in my
mind, threw doubt on the very existence of global warming. Last year,
following an intensive research effort involving a dozen scientists, I
concluded that global warming was real and that the prior estimates of
the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.

Yes, yes, I know, the finding itself is “dog bites man.” What makes this “man bites dog” is that Muller has been a skeptic of climate science, and the single biggest funder of this study is the “Charles G. Koch Charitable Foundation ($150,000).” The Kochs are the leading funder of climate disinformation in the world! It gets better:

Our results show that the average temperature of the
earth’s land has risen by two and a half degrees Fahrenheit over the
past 250 years, including an increase of one and a half degrees over
the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.These findings are stronger than those of the
Intergovernmental Panel on Climate Change, the United Nations group
that defines the scientific and diplomatic consensus on global warming.

In short, a Koch-funded study has found that the IPCC “consensus”
underestimated both the rate of surface warming and how much could be
attributed to human emissions!
Here is some background on BEST followed by a longer excerpt of the op-ed.
A group of scientists led by one well-known skeptic, Muller — and
whose only climatologist listed is Judith Curry, a well-known
confusionist [see Schmidt and Annan and Steig andVerheggen, and CP]
— decided to reexamine all of the temperature data they could get their
hands on. I broke the story of their initial findings in March 2011
(with the help of climatologist Ken Caldeira) – see Exclusive:
Berkeley temperature study results “confirm the reality of global
warming and support in all essential respects the historical temperature
analyses of the NOAA, NASA, and HadCRU.”
The top figure is an updated chart of their findings from March of this year. They found a lot of warming. Indeed, their key paper from 2011 found:

… our analysis suggests a degree of global
land-surface warming during the anthropogenic era that is consistent
with prior work (e.g. NOAA) but on the high end of the existing range of reconstructions.

So the only remaining question for BEST was: What is the cause of
that warming? Of course, those who read ClimateProgress or the
scientific literature already knew the answer to that question (see the
12/11 post, It’s “Extremely Likely That at Least 74% of Observed Warming Since 1950″ Was Manmade; It’s Highly Likely All of It Was).
BEST is set to release those findings this week. The excellent UK Guardian reporter, Leo Hickman,
tweeted earlier today that “Significant climate-related news will be
breaking on Guardian website in next 24-36 hours” and then he tweeted an
hour ago the link to the excerpt of Muller’s op-ed. Here is more of the op-ed:

How definite is the attribution to humans? The carbon
dioxide curve gives a better match than anything else we’ve tried. Its
magnitude is consistent with the calculated greenhouse effect — extra
warming from trapped heat radiation. These facts don’t prove causality
and they shouldn’t end skepticism, but they raise the bar: to be
considered seriously, an alternative explanation must match the data at
least as well as carbon dioxide does.

Well, in fact, to be seriously considered, an alternative explanation
must match the data at least as well as does CO2 — and it must offer
some mechanism that counteracts the well-known warming effect of CO2.
Not bloody likely.

The careful analysis by our team is laid out in five scientific papers now online at BerkeleyEarth.org.
That site also shows our chart of temperature from 1753 to the
present, with its clear fingerprint of volcanoes and carbon dioxide,
but containing no component that matches solar activity. Four of our
papers have undergone extensive scrutiny by the scientific community,
and the newest, a paper with the analysis of the human component, is
now posted, along with the data and computer programs used. Such
transparency is the heart of the scientific method; if you find our
conclusions implausible, tell us of any errors of data or analysis.
What about the future? As carbon dioxide emissions increase, the
temperature should continue to rise. I expect the rate of warming to
proceed at a steady pace, about one and a half degrees over land in the
next 50 years, less if the oceans are included. But if China continues
its rapid economic growth (it has averaged 10 percent per year over the
last 20 years) and its vast use of coal (it typically adds one new
gigawatt per month), then that same warming could take place in less than 20 years.
Science is that narrow realm of knowledge that, in principle, is
universally accepted. I embarked on this analysis to answer questions
that, to my mind, had not been answered. I hope that the Berkeley Earth
analysis will help settle the scientific debate regarding global
warming and its human causes.

Ouch.
I asked Caldeira for a comment on Muller’s op-ed. He writes:

I am glad that Muller et al have taken a look at
the data and have come to essentially the same conclusion that nearly
everyone else had come to more than a decade ago.
The basic scientific results have been established for a long time now, so I do not see the results of Muller et al
as being scientifically important. However, their result may be
politically important. It shows that even people who suspect climate
scientists of being charlatans, when they take a hard look at the data,
see that the climate scientists have been right all along.